【摘要】 揭示喀斯特灌丛生态系统土壤丛枝菌根真菌(arbuscular mycorrhizal fungi,AMF)群落及其对异质性生境与季节变化的响应规律,对合理利用土壤AMF促进喀斯特退化生境的恢复具有重要的意义。以桂西北喀斯特峰丛洼地1 hm2典型灌丛生态系统为研究对象,采用Illumina测序技术分析喀斯特灌丛两种主要小生境(石土面和土面)土壤AMF群落的季节变化特征及其影响因子。研究共发现AM真菌7科8属,球囊霉属/种为该地区优势属/种;土壤AMF群落组成结构季节差异显著(P<0.05),冬季土壤AMF的Shannon多样性和丰富度均高于夏季,但小生境类型及季节与生境类型的交互作用对多样性均无显著影响;冗余分析(Redundancy ananlysis,RDA)表明,速效磷、速效钾和植物丰富度极显著影响喀斯特灌丛土壤AMF群落组成结构(P<0.01)。研究结果为喀斯特地区合理利用植物与土壤AMF共生促进退化生境植被恢复提供了理论依据与实践指导。更多还原

【Abstract】 Understanding the variation of arbuscular mycorrhizal fungi(AMF) communities with heterogeneous habitats and seasonal changes are necessary for the rational use of plant symbiotic microorganisms to promote the restoration of degraded karst habitats. In the present study, seasonal variation of soil AMF communities and the influencing factors were investigated at two kinds of microhabitats(with rock exposure rates of >30% and <30%, respectively) within one hectare of karst shrubland in northwestern Guangxi. Illumina sequencing was used to determine AMF community structure and diversity. Eight genera and seven families of AMF were found. The genus Glomus and its species were the dominant genus and dominant species, respectively. Soil AMF community composition and structure were significantly distinct between summer and winter(P<0.05). The Shannon diversity and abundance of soil AMF communities in winter were higher than those in summer, respectively. The habitat type or the interaction between season and habitat type had no significant effect on AMF diversity. Redundancy analysis(RDA) showed that available phosphorus, available potassium and plant species richness significantly affected the composition and structure of soil AMF community in karst shrubland(P<0.01). The results provide theoretical basis for the rational use of plant and soil AMF symbiosis to promote the restoration of degraded vegetation in karst areas of southwest China.更多还原